The disadvantage of the using wind turbines, provided with a plurality of rotor blades, as wind power plants, resides in the fact that, for reasons of stability, the rotor blades which are exposed to the airflow have relatively small, tilted surfaces and hence can only utilize a small portion of the air-flow (quantity) available, and, moreover, the air disadvantageously does not strike the rotor blades at right angles but at an acute or obtuse angle.
Since there is also a continuous change of direction between the direction of the airflow and the position of the rotor blades when a rotor system is in operation, the efficiency is relatively low compared with the quantity of air flowing past.